Should You Have the Air Ducts in Your Home Cleaned?

Summer in North Carolina means two things: heat and humidity. Maybe the air conditioner in your home has not been able to keep up, so you call your regular HVAC servicing company. One of the things they might suggest is having your duct work cleaned to remove dust and mold spores and improve the air flow into your home. Is this really necessary?

Despite the claims of many companies that perform duct cleaning, it has never been proven to have any substantial health benefits. Addressing the other pollutants in your home such as cooking, cleaning products, smoking, or pets can often have a more immediate impact on the air quality inside your home.

What if the service provider tells you that your ductwork or your HVAC system is contaminated with mold?

Always ask to see it. Many areas within the HVAC system or ducts are not easily accessible. Even if you see a substance that you suspect is mold, remember that positively identifying mold requires testing and laboratory analysis. Mold on hard non-porous surfaces (such as sheet metal) can be cleaned, while contaminated insulation or other such materials will need to be replaced.

However, there are times when duct cleaning may be beneficial. You should consider having your air ducts professionally cleaned if:

• you can see large accumulations of suspected (or confirmed) mold growth
• there is an infestation of rodents or insects evident inside the ductwork
• visible discharge is emitted from your air supply vents when the system is running

If you determine that having the air ducts in your home cleaned is necessary, here are some tips from the Environmental Protection Agency on selecting a service provider :

• Do not hire duct cleaners who make sweeping claims about the health benefits of duct cleaning -- such claims are unsubstantiated. Do not hire duct cleaners who recommend duct cleaning as a routine part of your heating and cooling system maintenance. You should also be wary of duct cleaners who claim to be certified by EPA. EPA neither establishes duct cleaning standards nor certifies, endorses, or approves duct cleaning companies.
• Do not allow the use of chemical biocides or chemical treatments unless you fully understand the pros and the cons of the products being used.
• Check references to be sure other customers were satisfied and did not experience any problems with their heating and cooling system after cleaning.
• Contact your county or city office of consumer affairs or local Better Business Bureau to determine if complaints have been lodged against any of the companies you are considering.
• Interview potential service providers to ensurethat they are experienced in duct cleaning and have worked on systems like yours; they will use procedures to protect you, your pets, and your home from contamination; and they comply with the National Air Duct Cleaning Association's air duct cleaning standards.
• Ask the service provider whether they hold any relevant state licenses. The following states require air duct cleaners to hold special licenses: Arizona, Arkansas, California, Florida, Georgia, Michigan and Texas. Other states may soon require them as well.
• If the service provider charges by the hour, request an estimate of the number of hours or days the job will take, and find out whether there will be interruptions in the work. Make sure the duct cleaner you choose will provide a written agreement outlining the total cost and scope of the job before work begins.

Finally, remember that the best way to avoid needing to have the air ducts in your home cleaned is to prevent dirt and water from entering your heating and cooling system.


Air Matters has performed mold inspection and testing services in the Raleigh NC area since 2002. The owner, Renee Ward, has over 22 years of safety and environmental experience and holds both her Bachelor of Science and Masters degrees in engineering. Renee is also a member of the American Industrial Hygiene Association and the American Indoor Air Quality Council. Contact Air Matters at (919) 870-6748.